Phantom

Phantom is a boss character that appears in Devil May Cry and Devil May Cry 2. Phantom may have been one of the highest-ranking generals in the Devil Kingdom, but since no one has ever returned to tell tales, even more powerful devils could exist there. He is first encountered in Devil May Cry during Mission 3: Destroyer of Ardor and in Devil May Cry 2 during Dante's Mission 14 and Dante's Mission 18.

Description
Phantom resembles a spider, but its body is as gargantuan as an elephant's and its shell is harder than a rock. Its blood, when shed, is made of scorching lava reminiscent of the flaming rivers of Hell and this monster often leaves a trail of fire as it walks. He is one of Mundus' generals, seemingly of equal rank with a devil knight, and is considered his right-hand-"man", as well as the greatest threat of the Dark Army. Also, when its eyes change red, it changes into its scorpion form.

Devil May Cry
In his introduction, Phantom corners Dante, thinking him to be an ordinary human. As he confidently refers to Dante as a "disappointing catch," Dante comments on the demon's size and hopes that there is "something inside that big body of yours." Phantom is defeated by Dante and manages to escape. However, he continually pursues him over the course of Dante's stay on Mallet Island. Phantom is finally defeated when he crashes through a window on the roof, impaling himself on a statue below. Gazing at Dante, he sees Sparda's image and refuses to believe that the Dark Knight is still alive. Dante then tells him that he is not Sparda himself, but his son. Phantom dies soon after, melting into a pool of lava, unable to respond.

Devil May Cry 2
Phantom makes a brief appearance when emerges from a portal in the sky once the island has been brought closer to the Demon World. No explanation for this fight or his apparent return from the dead is given, though the Guidepost indicates that the portal may be a "door to the past". He has no dialogue either before, during, or after the fight. When defeated, he shatters into glass-like shards, and reappears as part of Argosax the Chaos.

Devil May Cry: The Animated Series
Phantom makes a cameo appearance in the opening animation for the Devil May Cry anime. There are actually two Phantoms in the screenshot, but Phantom himself is never encountered during the story. Oddly the opening has him bleeding actual blood and not lava.

Devil May Cry Volume 2
Phantom appears in Devil May Cry Volume 2. In a human form, he is described as "a squat bull of a man whose stance betrayed a fire that blazed stronger than the others". He also assumes his traditional demon form while fighting alongside Dante during the rebellion against Mundus.

Devil May Cry comic
In the Dreamwave comics version of Devil May Cry, it is revealed that Phantom tried to eat Dante as "only a demon of the highest order can initiate the evolution," implying that he devours other demons in order to grow stronger.

Bayonetta
In the game Bayonetta, directed by Hideki Kamiya, the creator of the original Devil May Cry, Bayonetta can summon a demon known as Phantasmaraneae that greatly resembles Phantom. This was intentional, as Kamiya claims that he sees Phantom as an offspring of Phantasmaraneae.

Devil May Cry
Phantom uses a variety of attacks during his boss fights. He has the ability to release fire balls from his mouth, call pillars of lava from the ground below the player's feet (referred to as "calling dead souls" within the game) and is able to leap great distances. He attempts to land on Dante and crush him with his great weight. Phantom also is able to unwind a long, scorpion-like tail from his back, which he can use to strike or swipe at the player. When the tail is not being used, it is curled up in the appearance of an abdomen. Being composed mainly of stone and volcanic rock, Phantom's only two weak points are his face and his back. When damaged enough, Phantom can shoot lava from his back much like a volcano. Any other attacks bounce off of his impenetrable skin, leaving the player open to attack. Using properly timed hits and dodges, one can quickly refill the Devil Trigger gauge by repeatedly hitting the hard shell and dodging away from attacks.

The easiest way to defeat Phantom is with Alastor's Air Raid ability. Flying high will keep you above most of his attacks while dealing high damage to him. If you do not have Air Raid, he is much harder. Focus on dodging his attacks and getting in small, 2-3 hit combos to his face when he pauses. It takes a long time to defeat him this way, but it is the safest method. Alternate strategies include standing on the Phantom while his tail is uncurled (which will help one avoid most of the Phantom's attacks) slicing or shooting quickly down. This is much easily accomplished with Air Hike. Another strategy involves timing one's hits perfectly to reflect the main magma ball strike back to the Phantom. The latter is very difficult, however, and should be used with caution.

Phantom chases Dante down corridors during two instances, once during the mission directly after his first fight, and once in the canals. The player can run from him inside a door, making him disappear, or, if Air Raid is in the player's possession, Phantom can easily be slain in order to get a large amount of red orbs, making this a possibility of farming them.

Phantom can also be fought repeatedly in the fountain room during the mission interlude from mission seven and eight as an optional boss on Hard and Dante Must Die mode.

Devil May Cry 2
Phantom's tactics are essentially the same as from Devil May Cry. The difference here is you don't have the same weapons with which to fight him. Aim for his face or back, and dodge his attacks. Be particularly careful of his "Calling Dead Souls" attack, as it can reach anywhere in the battlefield.

Trivia

 * Because of his rather frequent appearances in Devil May Cry and a reappearance in the second, he holds the distinction of being one of the most recurring bosses in the series, along with Nelo Angelo, Griffon, Nightmare and Vergil, all of which are fought three times.
 * If the two optional encounters with Phantom in the waterways and hallway are counted, he is the most recurring boss character in the entire series.